Nudibranch "Bloom"

Tom Nic · Post by **Tom Nic** » Tue May 29, 2007 2:07 pm

While diving at Sund Rock on Memorial Day Monday Sparky and I begin to come across small nudibranchs. There were abundant in the 30 to 40fsw range, not on the rock walls, but on the sediment. We saw one, then two, then three, then groups. We counted a dozen, then dozens, then scores, then easily hundreds of them through 2 dives. Most of them were concentrated to the North of the North Wall, and in the 30 to 50' range, but they were everywhere.

Following are a few shots: I beleive these are Opalescent Nudies, Hermissendra crassicornis

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/233/5203 ... 3184c6.jpg" width="500" height="406" alt="CIMG0887"></a>

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/228/5203 ... b69d3f.jpg" width="500" height="333" alt="CIMG0888"></a>

They were all different sizes, from a quarter inch to 2 inches. At first I thought that the one below was the Red Gilled Nudibranch, Flabellina verucosa . As I look closer, it might also be the Red Flabellina, Flabellina triophina, I'm not real positive. Gotshall says that the "main difference is that F. triophina has a pointed snout which is often upturned, and the cerrata are continuous on a flange ranther than in clusters." I guess with that description it looks more like Flabellina triophina.

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/251/5203 ... 5e6162.jpg" width="500" height="333" alt="CIMG0829"></a>

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/241/5203 ... ded737.jpg" width="500" height="333" alt="CIMG0865"></a>
<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/198/5203 ... 959391.jpg" width="286" height="500" alt="CIMG0854"></a>
<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/239/5203 ... 8690c9.jpg" width="500" height="278" alt="CIMG0818"></a>

How many can you count in this photo? I think I stopped at 10.

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/245/5203 ... 68ebcc.jpg" width="500" height="334" alt="CIMG0740"></a>

This one looks below more like the Flabellina verucosa, and with the ruler gives a better idea of size!

<a href="" title="Photo Sharing"><img src="http://farm1.static.flickr.com/239/5203 ... 7d0d51.jpg" width="500" height="373" alt="CIMG0958"></a>

More pictures are here.

Tangfish · Post by **Tangfish** » Tue May 29, 2007 2:32 pm

Tom, I've noticed a ton of these buggers out as well. Hey, that's a handy idea carrying a ruler around. I've had 'land-friends' ask me many times to provide scale in my photos.

Zen Diver · Post by **Zen Diver** » Tue May 29, 2007 3:20 pm

There were 100's of those guys at Pt Whiteny too, depths from 85-65 fsw mostly. Kind of creepy almost.

-Valerie

Tom Nic · Post by **Tom Nic** » Tue May 29, 2007 3:51 pm

'Tis the season, I guess?

thelawgoddess · Post by **thelawgoddess** » Tue May 29, 2007 4:15 pm

beautiful! lucky you!!!

Grateful Diver · Post by **Grateful Diver** » Tue May 29, 2007 8:55 pm

Sounder and I saw a nudibranch bloom at Cove 2 tonight ... clusters of Hermissenda Crassicornis ... one which was the biggest I've ever seen. Sadly, I didn't bring my camera, as we were playing with deco bottles.

... Bob (Grateful Diver)

LCF · Post by **LCF** » Tue May 29, 2007 9:45 pm

Last year, Kirk and I did a dive at Titlow around this time and spent over a half hour on ONE steel girder on the bottom, where we found dozens of nudibranchs, about six or eight different species, some we had never seen before. It must be a hatching kind of phenomenon. It's certainly great fun.

Sounder · Post by **Sounder** » Tue May 29, 2007 10:08 pm

It was really neat to see so many - and there really was a HUGE one that would have made for a great picture. Oh well - never fails that you see "the best shot" when you don't bring your camera.

We had a great dive though and I now have a new task-loading skill to practice. $\:D/$

Tom Nic · Post by **Tom Nic** » Wed May 30, 2007 7:35 am

Sounder wrote:It was really neat to see so many - and there really was a HUGE one that would have made for a great picture. Oh well - never fails that you see "the best shot" when you don't bring your camera. $\:D/$

You did get them to promise to stay there until our Friday dive, right? What, you don't talk to nudibranchs?

Grateful Diver · Post by **Grateful Diver** » Wed May 30, 2007 8:03 am

Hopefully I will be taking some nice nudibranch shots on Friday at Redondo ... the one in California ... $\:D/$

... Bob (Grateful Diver)

Sounder · Post by **Sounder** » Wed May 30, 2007 8:27 am

Or Deadman's Wall... also in California

nwscubamom · Post by **nwscubamom** » Wed May 30, 2007 8:49 pm

The abundance of those nudis in Hood Canal is pretty common - it doesn't seem to be a seasonal difference, but it does seem to be related to depth.

I often find them in a narrow band of about 20 feet, usually around the 70-50 foot depth though. I'm not sure why they like to hang out there - and it only seem to be Hood Canal sites that have the abundance of that species all concentrated in one band like that. It's pretty cool, and you're right - there's just hundreds of them!!

Great pics!

- Janna

Tom Nic · Post by **Tom Nic** » Wed May 30, 2007 9:45 pm

nwscubamom wrote:The abundance of those nudis in Hood Canal is pretty common - it doesn't seem to be a seasonal difference, but it does seem to be related to depth.

I often find them in a narrow band of about 20 feet, usually around the 70-50 foot depth though. I'm not sure why they like to hang out there - and it only seem to be Hood Canal sites that have the abundance of that species all concentrated in one band like that. It's pretty cool, and you're right - there's just hundreds of them!!

Great pics!

- Janna

Are you saying that it is not related to time of year? Do you know anything about when or how often they "hatch"?

nwscubamom · Post by **nwscubamom** » Wed May 30, 2007 10:00 pm

Pretty sure it's not related to time of year. And no, sorry, I don't know anything about when they 'hatch', but I'd think they'd be a LOT smaller than that if they were newly hatched.

- Janna

Tom Nic · Post by **Tom Nic** » Thu May 31, 2007 8:39 am

nwscubamom wrote:Pretty sure it's not related to time of year. And no, sorry, I don't know anything about when they 'hatch', but I'd think they'd be a LOT smaller than that if they were newly hatched.

- Janna

I know that I have been very impressed this year as the water warms with all the critters "coming back" from whereever it is they spend the winter out of my sight! It's all very new to me as last year I was concentrating more on just figuring out how to dive without causing harm to myself or others! ...so I'm seeing it all kind of for the first time. You vets have been watching this year after year!

I love it! The underwater seasons, if you will...

There were actually a bunch of very small nudi's, in the few centimeter range. I only took pics of the larger ones. You would see them of many different sizes, including lots of very small ones. I wonder what their life span and growth rate is...

So many questions!

$\:D/$